Camera

ABSTRACT

A camera has a first charge mechanism for charging a mirror, a second charge mechanism for charging an aperture diaphragm, a third charge mechanism for charging a shutter, an exposure preparation mechanism for performing an exposure preparation operation in response to a releasing operation, a selector for distinguishing between single-shot photographing and continuous photographing, a first detector for detecting completion of charging of the mirror, a second detector for detecting completion of charging of the aperture diaphragm, a third detector for detecting completion of charging of the shutter, and a controller for executing a flow of control such that, when the selector detects continuous photographing being performed and in addition the first and second detectors detect completion of charging of the mirror and the aperture diaphragm, the exposure preparation operation is started irrespective of the result of detection by the third detector.

This application is based on application No. H10-258326 filed in Japanon Sep. 11, 1998, the entire content of which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a camera having a continuousphotographing capability.

2. Description of the Prior Art

Conventionally, high-speed continuous photographing is achieved byspeeding up the individual operations, such as charging and filmfeeding, performed inside a camera and thereby speeding up the operationof the camera as a whole. However, in a conventional camera design, inwhich a new releasing operation can be started only after completion ofcharging and film feeding, it is impossible to achieve an operationspeed above a certain limit. For this reason, various attempts have beenmade to achieve a higher operation speed by improving the flow ofcontrol over an entire photographing sequence.

For example, according to U.S. Pat. No. 4,679,925, in continuousphotographing, exposure preparation operations are started beforecompletion of film feeding, provided that charging necessary to drivethe mirror, the aperture diaphragm, the shutter, and the taking lens hasalready been completed.

However, in this arrangement, exposure preparation operations arestarted only after completion of all kinds of charging including thosewhich are not necessary from the viewpoint of a photographing sequence,and this causes an unnecessary delay in starting exposure controloperations.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a camera capable ofperforming continuous photographing at higher speed.

To achieve the above object, according to one aspect of the presentinvention, a camera is provided with: a first charge mechanism forcharging a mirror; a second charge mechanism for charging an aperturediaphragm; a third charge mechanism for charging a shutter; an exposurepreparation mechanism for performing an exposure preparation operationin response to a releasing operation; a selector for distinguishingbetween single-shot photographing and continuous photographing; a firstdetector for detecting completion of charging of the mirror; a seconddetector for detecting completion of charging of the aperture diaphragm;a third detector for detecting completion of charging of the shutter;and a controller for executing a flow of control such that, when theselector detects continuous photographing being performed and inaddition the first and second detectors detect completion of charging ofthe mirror and the aperture diaphragm, the exposure preparationoperation is started irrespective of the result of detection by thethird detector.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other objects and features of the present invention will becomeclear from the following description, taken in conjunction with thepreferred embodiments with reference to the accompanying drawings inwhich:

FIG. 1 is a system configuration diagram of an entire camera embodyingthe present invention;

FIG. 2 is a perspective view of the film winding mechanism of the cameraof the embodiment;

FIG. 3 is a sectional view of a portion around the film driving motor ofthe camera of the embodiment;

FIGS. 4A, 4B, and 4C are plan views illustrating the action, for filmwinding, film rewinding, and switching between them, respectively, ofthe drive force transmitting mechanism of the camera of the embodiment;

FIG. 5 is a perspective view illustrating the action of the chargemechanism of the camera of the embodiment;

FIG. 6 is a sectional view, as seen from above, showing the outline ofthe structure of the entire camera of the embodiment;

FIG. 7 is a flow chart of the initial loading routine;

FIG. 8 is a flow chart of the SW1 interrupt handling routine;

FIG. 9 is a flow chart of the AF pulse interrupt handling routine;

FIG. 10 is a flow chart of the rewinding routine;

FIG. 11 is a flow chart of the first portion of the pulse 1 interrupthandling routine 1;

FIG. 12 is a flow chart of the second portion of the pulse 1 interrupthandling routine 1;

FIG. 13 is a flow chart of the pulse 2 interrupt handling routine 1;

FIG. 14 is a flow chart of the reverse energizing interrupt handlingroutine;

FIG. 15 is a flow chart of the SW4 interrupt handling routine;

FIG. 16 is a flow chart of the timer TMR2 interrupt handling routine;

FIG. 17 is a flow chart of the pulse 2 interrupt handling routine 2;

FIG. 18 is a flow chart of the pulse 1 interrupt handling routine 2;

FIG. 19 is a flow chart of the timer TMR2 interrupt handling routine 2;

FIG. 20 is a flow chart of the reverse energizing start time adjustmentroutine;

FIG. 21 is a time chart illustrating how the reverse energizing starttime adjustment routine proceeds;

FIG. 22 is a flow chart of the SW2 interrupt handling routine;

FIG. 23 is a flow chart of the SW2 interrupt handling routine;

FIG. 24 is a flow chart of the SW2 interrupt handling routine; and

FIG. 25 is a flow chart of the IP timer interrupt handling routine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention will be describedwith reference to the accompanying drawings. FIG. 6 is a sectional view,as seen from above, schematically showing the overall structure of anentire camera embodying the invention. In this figure, reference numeral70 represents the body of the camera. In a lower central portion of thebody 70 is formed an exposure frame 70 a that indicates thephotographing view field. On the left of the exposure frame 70 a isformed a film cartridge chamber 70 b into which a film cartridge 74having a roll of film housed therein can be loaded. On the right of theexposure frame 70 a is formed a spool chamber 70 c in which a spool 27and other components are housed.

In an appropriate position in the inner (i.e. facing the top side of thefigure) side wall of the film cartridge chamber 70 b is formed a smallhole 70 d, through which a film cartridge detecting pin 65 is placed soas to be protrusible from the wall. The film cartridge detecting pin 65is loaded with a force that tends to press it into the film cartridgechamber 70 b by a film cartridge detecting armature 67. The filmcartridge detecting armature 67, together with another film cartridgedetecting armature 66, constitutes a switch SW5. When the film cartridge74 is absent, the film cartridge detecting armatures 66 and 67 arelocated away from each other, and thus the switch SW5 is in an offstate; when the film cartridge 74 is loaded, it presses the filmcartridge detecting pin 65 toward the film cartridge detecting armature66 against the force exerted by the film cartridge detecting armature67, until eventually the film cartridge detecting armatures 66 and 67make contact with each other, thereby bringing the switch SW5 into an onstate.

Substantially at the center of the spool chamber 70 c is provided aspool 27 for winding photographic film F. The spool 27 has a claw 27 bthat engages with one of the perforations Fp formed in the film F topermit the film F to be easily caught around the spool 27 when it startsbeing wound.

Inside the spool 27 is arranged, concentrically therewith, a filmwinding motor 1 for driving the spool 27 in a manner as will bedescribed later. In an appropriate position on the circumferentialsurface of the spool 27, preferably near the location at which the filmF makes one turn around the spool 27, is arranged a film pressing rollersupport plate 57, which has, at its tip end 57 a, a film pressing roller56 fitted rotatably. The tip end 57 a of the film pressing rollersupport plate 57 is loaded with a force by a spring (not shown) in sucha way that the film pressing roller 56 is kept in contact with thecircumferential surface of the spool 27 so as to allow the film F to bewound tight around the spool 27.

Between the exposure frame 70 a and the spool 27 are arranged a sprocket50 that is rotated by the film F being transported and a guide roller 55that faces the sprocket 50 so as to allow the film F to be held betweenthem as it is transported. The sprocket 50 has a toothed portion 50 athat engages with the perforations Fp of the film F, and this permitsthe sprocket 50 to be rotated by the film F being transported. As thesprocket 50 rotates, a sprocket switch circuit board 51 shown in FIG. 2rotates together. A pattern formed on the sprocket switch circuit board51, together with sprocket switch armatures 52 and 53, constitutes aswitch SW3. This switch SW3 is turned on and off repeatedly to outputpulses while the film F is transported one frame. In this embodiment,eight pulses are generated for one frame.

Moreover, between the exposure frame 70 a and the spool 27, in anappropriate position in the side wall of the body 70, is formed a smallhole 70 e, through which a film detecting pin 60 is placed so as to beprotrusible from the wall. The film detecting pin 60 is loaded with aforce that tends to press it toward the film F by a film detectingarmature 62. The film detecting armature 62, together with another filmdetecting armature 61, constitutes a switch SW6. When the film F is noton the film detecting pin 60, or when a back lid (not shown) of thecamera is open and thus the film F is not pressed onto the body 70 by apressing plate 71 fitted on the back lid, the film detecting armatures61 and 62 are located away from each other, and thus the switch SW6 isin an off state.

When the film F is on the film detecting pin 60 and in addition the backlid is shut with the film F pressed onto the body 70 by the pressingplate 71, the film F presses the film detecting pin 60 toward the filmdetecting armature 61 against the force exerted by the film detectingarmature 62, until eventually the film detecting armatures 61 and 62make contact with each other, thereby bringing the switch SW6 into an onstate.

Immediately in front of the exposure frame 70 a is arranged a shutter 72having two shutter blades, called the first and second bladesrespectively. Reference numeral 101 represents a charge motor foractuating the shutter 72, an aperture diaphragm (not shown), and amirror mechanism (not shown) and also for restoring (i.e. charging) themto their initial position. Reference numeral 102 represents a chargemechanism driven by the charge motor 101. Reference numeral 73represents a battery serving as a power source for supplying electricpower to whichever portion of the camera requires it.

In FIG. 3, a winding tool 80, indicated by dash-and-dot lines, permitschecking of the action of the film winding mechanism without energizingthe film winding motor 1. The winding tool 80 has a gear 80 a fitted atits tip end. In an appropriate position in a winding base plate 17 isformed a hole 17 c, into which the gear 80 a of the winding tool 80fitted.

When the gear 80 a of the winding tool 80 is fitted into the hole 17 c,the gear 80 a meshes with an encoder gear 5. In this state, by rotatingthe winding tool 80, it is possible to adjust or inspect the action ofthe film winding mechanism, or check how it works, without actuallydriving the film winding motor 1. In addition, this permits operationfrom the outside, and thus helps save cost and space.

Next, the film winding mechanism will be described with reference toFIGS. 2 and 3. FIG. 2 is a perspective view of the film windingmechanism of the camera of the embodiment, and FIG. 3 is a sectionalview of a portion around the film driving motor of the camera of theembodiment. FIGS. 4A, 4B, and 4C are diagrams illustrating the action,for winding, rewinding, and switching, respectively, of the drive forcetransmitting mechanism of the camera of the embodiment.

As shown in detail in FIGS. 2 and 3, the film winding motor 1 isarranged inside the spool 27, and is, at its bottom, fixed to a supportbase 10 with motor fitting screws 9 and 9. The motor support base 10 iscoupled to and thereby fixed to the body 70 by being fitted aroundsupport base fitting screws 13 and 13 having elastic members 11 and 11provided around them. These elastic members 11 and 11 allow the motorsupport base 10 to move slightly in both vertical and horizontaldirections, and thereby help minimize the vibration that is transmittedto the body 70 as the film winding motor 1 rotates.

Moreover, between an upper portion of the motor shaft 1 a of the filmwinding motor 1 and a spool support base 15 fixed to the body 70 isprovided an elastic member 12. This elastic member 12 restricts themovement of the upper portion of the film winding motor 1, and alsominimizes the vibration that is transmitted to the spool support base 15and to the body 70 as the film winding motor 1 rotates. The spoolsupport base 15 has a rotation support portion 15 a for rotatablysupporting a spool rest 14 that rotates together with the spool 27.

On the other hand, on a lower portion of the motor shaft 1 a of the filmwinding motor 1 is provided a gear 1 b that rotates together with themotor shaft 1 a. This gear 1 b meshes with a toothed portion 2 a of areduction gear 2. The reduction gear 2 has, at its top, an upperprojection 2 b that is fitted into a hole 10 a formed in the motorsupport base 10, and has, at its bottom, a hole 2 c into which a pin 17a swaged into the winding base plate 17 is fitted.

In appropriate positions on the body 70 are provided bosses 70 f and 70f, and the winding base plate 17 is fixed to the tip ends of thosebosses 70 f and 70 f with winding base plate fitting screws 18 and 18that are screwed into the bosses 70 f and 70 f. The pin 17 a is looselyfitted into the hole 2 c formed at the bottom of the reduction gear 2.As described previously, whereas the motor support base 10 can moveslightly in both vertical and horizontal directions, the winding baseplate 17 is fixed to the body 70. Thus, when the motor support base 10moves in a horizontal direction, the reduction gear 2 is inclinedslightly. However, in the structure described above, a slightinclination of the reduction gear 2 does not affect the rotation of thereduction gear 2.

Moreover, the toothed portion 2 a of the reduction gear 2 and the upperprojection 2 b thereof are relatively close to each other, andtherefore, even if the motor support base 10 moves in a horizontaldirection, the gear 1 b of the film winding motor 1 and the toothedportion 2 a of the reduction gear 2 are kept in a properly meshed stateso as not to disengage from each other. In this way, a simplevibration-proof structure is adopted that does not require varying thecenter-to-center distance between the gear 1 b and the reduction gear 2.This helps enhance durability, reduce wear and noise between gears, andsuppress vibration effectively.

Around a central shaft 2 d of the reduction gear 2 is provided a torsioncoil spring 3, and thus the rotation of the reduction gear 2 istransmitted through this torsion coil spring 3 to a reduction gear 4.The bottom end 3 a of the torsion coil spring 3 is held between stoppers4 a provided on the top surface of the reduction gear 4. When therotation of the reduction gear 2 is transmitted to the reduction gear 4,the reduction gear 4 transmits its rotation to the encoder gear 5 and toa gear 20. If, while the reduction gear 2 is rotating clockwise, anunduly large load as resulting from the film F being strained at itstail end or the like is applied to the reduction gear 4, slipping occursbetween the torsion coil spring 3 and the reduction gear 4 so that norotation will be transmitted.

The encoder gear 5 is rotatably supported by a boss 70 g provided on thebody 70 and a shaft 17 b swaged into the winding base plate 17, and hasa pulse plate 5 a arranged concentrically. A photointerruptor 6 has alight emitter and a light sensor arranged a predetermined distance apartfrom each other, with the pulse plate 5 a placed therebetween. As thepulse plate 5 a rotates, the photointerruptor 6 generates pulses. Thesepulses are output in synchronism with the rotation of the film windingmotor 1. However, when the reduction gear 4 stops rotating as a resultof the film F being strained at its tail end or the like, thephotointerruptor 6 stops outputting pulses.

As shown in FIG. 2, above the gear 20, a planet lever 22 is provided soas to be rotatable concentrically therewith, and the gear 20 meshes witha planet gear 21 pivoted on a tip end portion of the planet lever 22.When the gear 20 rotates counter-clockwise, the planet gear 21 mesheswith a large gear portion 23 a of a spool drive gear 23 (as indicated bysolid lines in the figure). By contrast, when the gear 20 rotatesclockwise, the planet gear 21 meshes with a gear portion 30 a of a camgear 30 (as indicated by dash-and-dot lines in the figure). The spooldrive gear 23 has a small gear portion 23 b, which meshes with an innergear 27 a formed integrally in the inner wall of the spool 27 so as torotate the spool 27.

The spool drive gear 23 has its lower portion 23 c placed through acylindrical spring barrel 25. Around the lower portion 23 c of the spooldrive gear 23 is wound a torsion coil spring 24. The torsion coil spring24 has an arm 24 a, which is held in a notch 25 a formed in the springbarrel 25, and thus the spring barrel 25 rotates concentrically togetherwith the spool drive gear 23.

Around the spring barrel 25 is wound a torsion coil spring 26, which hasone arm 26 a fixed to the boss 70 g provided on the body 70 and has theother arm 26 b placed so as to face a bent portion 36 a provided in arewinding planet lever 36 that is rotatable concentrically with a gear35 with which the gear 20 meshes. When the spool drive gear 23 rotatescounter-clockwise, the spool 27 also rotates counter-clockwise andthereby winds the film F.

This rotation acts to tighten the torsion coil spring 24, and thus thespring barrel 25 rotates counter-clockwise together with the spool drivegear 23 and the torsion coil spring 24. On the other hand, the samerotation acts to loosen the torsion coil spring 26, and thus slippingoccurs between the spring barrel 25 and the torsion coil spring 26. Theslipping torque in this loosening direction is set to be smaller thanthe slipping torque in the tightening direction of the torsion coilspring 24, and this makes it possible to rotate the spring barrel 25together with the spool drive gear 23.

When the planet gear 21 is not meshed with the large gear portion 23 aof the spool drive gear 23, the film F wound around the spool 27 tendsto become loose owing to its own resilience and thereby gives the spool27 and the spool drive gear 23 a rotational force that tends to rotatethem clockwise. This force acts to loosen the torsion coil spring 24 andtighten the torsion coil spring 26, and therefore the slipping torque inthe tightening direction of the torsion coil spring 26 becomes fargreater than the slipping torque in the loosening direction of thetorsion coil spring 24, preventing the spring barrel 25 from rotatingclockwise.

Thus, slipping occurs between the torsion coil spring 24 and the spooldrive gear 23. However, the slipping torque here is set to be greaterthan the above-mentioned force due to the resilience of the film F thattends to rotate the spool 27 clockwise, and therefore the spool 27 isnot allowed to rotate clockwise. This prevents the film F wound aroundthe spool 27 from becoming loose owing to its own resilience. Thisstructure helps reduce loss in the winding force, increase the windingspeed, and make efficient use of the battery power. To minimize loss inthe winding force, it is preferable to use a complete one-directionalclutch in place of the torsion coil springs that are used in thisembodiment to exploit the difference in their slipping torque.

When the other arm 26 b of the torsion coil spring 26 is pressed in itsloosening direction by the bent portion 36 a of the planet lever 36 (asindicated by broken lines in FIG. 2), the torque that acts to tightenthe torsion coil spring 26 becomes zero, and thus the spring barrel 25is allowed to rotate clockwise together with the spool drive gear 23 andthe torsion coil spring 24. In this way, during rewinding (describedlater) of the film F, when the spool 27 and the spool drive gear 23 arerotated clockwise by the film F being rewound, they are saved from anundue load. This structure helps reduce loss in the rewinding force,reduce rewinding time, and make efficient use of the battery power.

The gear 35 has a rewinding planet lever 36 provided so as. to berotatable concentrically therewith, and meshes with a rewinding planetgear 37 pivoted on a tip end portion of the rewinding planet lever 36.The rewinding planet lever 36 is loaded with a force that tends torotate it clockwise by a spring 38. The force exerted by the spring 38is set to be strong enough to press the arm 26 b of the torsion coilspring 26 in its loosening direction (from the position indicated bysolid lines to the position indicated by broken lines in FIG. 2).

At the bottom of the cam gear 30, a circuit board (not shown) having apredetermined pattern printed thereon is fitted so as to be rotatabletogether therewith. The pattern formed on this circuit board, togetherwith cam switch armatures 31 and 32, constitutes a switch SW8. Theswitch SW8 is in an on state or in an off state in accordance withwhether a cam portion 30 b of the cam gear 30 is in the position shownin FIG. 4A or in the position shown in FIG. 4C, respectively.

FIG. 4A shows the state observed during winding of the. film F, FIG. 4Bshows the state observed during switching from winding to rewinding ofthe film F, and FIG. 4C shows the state observed during rewinding of thefilm F. Hereafter, the action of this mechanism will be described. Theindividual gears are designed to have an appropriate number of teeth soas to maintain a predetermined relationship among them that achieves theaction as described below. The phase of the cam portion 30 b of the camgear 30 is set in advance in such a way that, in the state shown in FIG.4A, the cam portion 30 b lies in the position as shown in that figure.

In FIG. 4A, the reduction gear 4 rotates clockwise. The rewinding planetlever 36 has a projection 36 b, which is loaded with a force that tendsto rotate it clockwise by the spring 38 and is thereby kept in contactwith the cam portion 30 b formed integrally with the cam gear 30.Therefore, the rewinding planet lever 36 cannot rotate furtherclockwise, and thus the rewinding planet gear 37 is located away from arewinding gear 39.

In this state, when the reduction gear 4 rotates clockwise, and thus thegear 20 rotates counter-clockwise, the planet lever 22 rotatescounter-clockwise until the planet gear 21 meshes with the large gearportion 23 a of the spool drive gear 23, and then strikes a stopper (notshown). FIG. 4A shows this state. In this state, when the reduction gear4 is rotated clockwise so as to wind the film F, this rotation istransmitted through the gear 20 and the reduction gear 21 to the largegear portion 23 a of the spool drive gear 23, causing the spool drivegear 23 to rotate counter-clockwise. As a result, the spool 27 rotatescounter-clockwise and thereby winds the film F.

In FIG. 4B, the reduction gear 4 rotates counter-clockwise. In the stateshown in FIG. 4A, when the reduction gear 4 rotates counter-clockwise,the planet lever 22 disengages the planet gear 21 from the large gearportion 23 a of the spool drive gear 23 and rotates clockwise until itstrikes a stopper (not shown) and engages the planet gear 21 with thecam gear 30. At this time, the planet gear 21 rotates counter-clockwise,and thus the cam gear 30 rotates clockwise. As a result, the cam portion30 b of the cam gear 30 rotates clockwise and thereby releases theprojection 36 b of the rewinding planet lever 36.

When the projection 36 b is released, the rewinding planet lever 36 isrotated clockwise by the spring 38, and thus the rewinding planet gear37 meshes with the rewinding gear 39. How the rewinding planet gear 37meshes with the rewinding gear 39 is set by the rewinding planet lever36 striking a stopper (not shown). As the rewinding planet lever 36rotates clockwise, the bent portion 36 a rotates the other arm 26 b ofthe torsion coil spring 26 counter-clockwise. This allows the spool 27to be left in a no-load state, i.e. in an idly rotating state, duringrewinding (FIG. 4C). In this state, the reduction gear 4 continuesrotating until the cam portion 30 b of the cam gear 30 reaches theposition shown in FIG. 4C.

In FIG. 4C, the reduction gear 4 rotates clockwise. In the state shownin FIG. 4B, when the reduction gear 4 starts rotating clockwise, theplanet lever 22 disengages the planet gear 21 from the cam gear 30 andstarts rotating counter-clockwise. However, when the gear 20 rotatescounter-clockwise, while the planet lever 22 is rotatingcounter-clockwise, a side portion 22 a thereof opposite the planet gear21 strikes a side portion 36 c of the planet lever 36 and thereby keepsthe planet gear 21 and the large gear portion 23 a of the spool drivegear 23 away from each other. As a result, the reduction gear 21 is leftin an idly rotating state. On the other hand, the rewinding planet gear37 is meshed with the rewinding gear 39, and thus the clockwise rotationof the reduction gear 4 is transmitted to the rewinding gear 39.

Back in FIG. 2, the rewinding gear 39 transmits its rotation through arewinding gear train 40 to a rewinding fork gear 41. On the rewindingfork gear 41 is arranged a rewinding fork 42 that rotates together withthe rewinding fork gear 41 and that engages with a key formed in thefilm cartridge 74 described previously. By the clockwise rotation of therewinding fork 42, the film F is rewound into the film cartridge 74.

Next, the charge mechanism will be described with reference to FIG. 5.In this figure, reference numeral 101 represents the charge motordescribed previously, which rotates a charge cam 112 through a reductiongear 111. Reference numeral 117 represents a charge lever for theaperture diaphragm, the mirror, and the shutter. When charging iscomplete, the charge lever 117 is locked in the position (B) shown inthe figure. When a releasing magnet (not shown) is activated, the chargelever 117 is unlocked and moves in the direction (A). At this time, theaperture diaphragm is stopped down, and the mirror is lifted up. Theshutter 72 shown in FIG. 6 is locked by a magnet until the stopping downof the aperture diaphragm and the lifting up of the mirror are complete,and is thus allowed to start running, by de-energizing the magnet, onlya predetermined period of time thereafter.

The charge cam 112 has a cam 112 a that is so formed that its radiusincreases as it rotates. Kept in contact with this cam 112 a is a tipend portion 115 a of a lever 115 that is loaded with a force that tendsto rotate it clockwise by a spring 116. As the charge cam 112 rotatesclockwise, the lever 115 rotates counter-clockwise, and thereby thecharge lever 117 is pressed in the direction (B). This causes theaperture diaphragm to be opened fully, the mirror to be brought down,and the shutter to be charged.

When the charge cam 112 makes substantially one turn, charging iscomplete. The charge lever 117 remains locked by the lever 115, andtherefore stops when the lever 115, rotated clockwise by the spring 116,falls into that portion of the cam 112 a of the charge cam 112 where itsradius is smallest. The charge cam 112 has, at its bottom, a charge camswitch circuit board (not shown) fitted so as to be rotatable togetherwith the charge cam 112. A pattern formed on the charge cam switchcircuit board, together with charge cam switch armatures 113 and 114,constitutes a switch SW4.

This switch SW4 is in an on state when charging is complete. The switchSW4 is turned off immediately after the charge motor 101 is energizedand charging is started, and is turned on when the charge cam 112 makessubstantially one turn and charging is complete. When the switch SW4 isturned from off to on, braking is applied to the charge motor 101 byde-energizing it.

On the other hand, the pattern formed on the charge cam switch circuitboard, together with charge cam switch armatures 114 and 118,constitutes a switch SW9. This switch SW9 is turned on when charging ofthe mirror and the aperture diaphragm is complete. A detaileddescription will be given later. Note that, here, the charge cam switcharmature 114 is connected to ground GND. Note also that, though notshown, a switch SW1o for allowing the user to turn on and off thecontinuous photographing mode at hand is formed in the body of thecamera.

FIG. 1 is a system configuration diagram of a camera embodying thepresent invention. Reference numeral 601 represents a camera controlmicrocomputer (hereafter referred to as the CPU) for achieving functionssuch as controlling operation routines of the entire camera, controllingcalculations related to exposure, and controlling calculations relatedto automatic focusing (abbreviated to AF). The CPU 601 is built as asystem incorporating RAM (random-access memory), ROM (read-only memory),a timer, a serial I/O (input/output) handler, an A/D (analog-to-digital)converter, and I/O ports, and is provided with data buses and variousI/O terminals D1 to D26 as will be described below. Reference numeral602 represents an interface (hereafter referred to as the I/O IC) fortransferring instructions from the CPU 601 to various portions of thecamera and transferring signals from various portions of the camera tothe CPU 601.

Reference numeral 603 represents a focus detection module for measuringthe amount of defocus observed in the object image formed on the film oran equivalent plane thereof, and is composed of a one-dimensionalself-scanning-type image sensor (hereafter referred to as the CCD(charge-coupled device)), a CCD driver, an A/D converter, an A/Dconversion reference voltage source, and other components. The analogimage data obtained from the CCD is first converted into digitalsignals, which are then fed by way of an AF data bus to the CPU 601.

Reference numeral 604 represents a display composed of an LCD (liquidcrystal display) or LEDs (light-emitting diodes) for displaying theshutter speed Tv and the aperture value Av fed, as results ofcalculations to be used for AE (automatic exposure), from the CPU 601,the photographing mode, and other data. Reference numeral 605 representsa lens data circuit that is incorporated in a taking lens to store theopen aperture value, the maximum aperture value, the focal length, therotating/linear movement amount conversion coefficients necessary forfocus adjustment, and other data. When the taking lens is fitted to thecamera body, such data is transferred to the camera body via electriccontacts provided near where they are fitted together.

Reference numeral 606 represents a photometer for measuring thebrightness Bv of the object, and is composed of a light-sensingphotoelectric conversion device, an A/D converter, an A/D conversionreference voltage source, a data handler for communicating data with theCPU 601, and other components. In accordance with instructions fed fromthe CPU 601, the photometer 606 performs photometry on the light thathas passed through the taking lens. Reference numeral 607 represents afilm sensitivity reader for automatically reading the sensitivity of thefilm loaded, and reads the film sensitivity indicated on the filmcartridge, in which the film is housed, via electric contacts providedin the film cartridge chamber 70 b of the camera. Reference numeral 608represents non-volatile memory (hereafter referred to as the EEPROM(electrically-erasable programmable read-only memory)) that permits thedata written thereto to be erased electrically in response to aninstruction from the CPU 601.

The above-mentioned display 604, lens data circuit 605, photometer 606,film sensitivity reader 607, and non-volatile memory 608 are connectedto the serial I/O handler of the CPU 601 by way of a serial data bus.

Reference symbols SW1 to SW10 represent switches. These switches aregrounded at one terminal thereof and, at the other terminal thereof,connected to the input terminals D1 to D10 of the I/O ports of the CPU601 by way of signal lines S1 to S10, respectively. When the switchesSW3 and SW4 change their state from off to on, the CPU 601 detects thisstate change and requests an interrupt.

The I/O ports of the CPU 601 further include output terminals D11 to D13for feeding out commands CMDO to CMD2 for controlling a film windingmotor M1 (corresponding to the film winding motor 1 mentionedpreviously), output terminals D14 and D15 for feeding out commands CMD3and CMD4 for controlling a charge motor M2 (corresponding to the chargemotor 101 mentioned previously) for charging the aperture diaphragmlocking member, the mirror, and the shutter, and output terminals D16 toD19 for feeding out commands CMD5 to CMD8 for controlling variousmagnets.

The CPU 601 incorporates a plurality of timers. Those timers are eachcomposed of a counter that is incremented by an external or internalclock and a register that stores a value with which the value counted bythe counter is compared constantly so that, when the count valuecoincides with the register value, an interrupt will be requested. Inthis embodiment, pulses 1 (the pulses output from the photointerruptor 6mentioned previously) are fed to the input terminal D21 for receiving anexternal clock for the timers so that the pulses 1 will be counted, and,every time a pulse 1 is received, an interrupt is requested. Moreover,timers TMR1, TMR2, and TMR3 are used that count time in synchronism withan internal clock.

Reference symbol RESET represents a reset terminal that is normally keptequal to +V_(DD) by a pull-up resistor R1, and, when the level at thisterminal turns from a low level to a high level, the CPU 601 is reset.Reference numeral 609 represents a clock pulse generating circuit forfeeding a clock signal to the CPU 601, and has a resonator X. The outputterminals D24 and D25 are used to feed out commands CMD9 and CMD10 forcontrolling a motor driver for driving a lens drive motor M3 (not shownin pictorial drawings), and the output terminal D26 is used to feed outa command CMD11 for controlling an imprinting module for imprinting adate in response to an IP (imprint) output.

Next, the I/O IC 602 and various controllers will be described.Reference symbols 1CMg and 2CMg represent magnets for holding the firstand second blades (not shown) of the shutter. When a low-level signal isfed out via the output terminal P23 or P22, the magnets 1CMg or 2CMg isenergized and thereby the first or second blade is held, respectively.The period of time that passes after the first blade is released untilthe second blade is released corresponds to the shutter speed Tv.

Reference symbol FMg represents a magnet for locking the aperturediaphragm (not shown). When a low-level signal is fed out via the outputterminal P21, the magnet FMg is energized and thereby the aperturediaphragm locking member is held; when the aperture diaphragm lockingmember is released, it moves back to a predetermined position where itis locked. Reference symbol RMg represents a magnet for releasing. Whena low-level signal is fed out via the output terminal P20 for apredetermined period of time, a releasing member is unlocked, theaperture diaphragm is stopped down, and the mirror is lifted up so as tobe retracted from the optical path.

Reference symbol PI1 represents a component that corresponds to thephotointerruptor 6 described previously. This component PI1 outputspulses, which are, as they pass through a waveform shaper 602 a providedwithin the I/O IC 602, formed into the pulses 1, and are then output viathe output terminal P18 so as to be fed to the input terminal D21 of theCPU 601. Reference symbol PI2 represents a component that outputs pulsesthat an encoder generates as it rotates when the aperture diaphragm (notshown) is unlocked so as to represent the degree to which the aperturediaphragm is stopped down. These pulses, similarly, are subjected towaveform shaping by the waveform shaper 602 a and are then output viathe output terminal P25 so as to be fed to the input terminal D20.

Reference symbols Q1 to Q6 represent transistors for driving the filmwinding motor M1. The film winding motor M1 has two coils of differenttypes inside it, of which one offers a high torque at a low rotationspeed (hereafter referred to as the L-type characteristics) and theother offers a low torque at a high rotation speed (hereafter referredto as the H-type characteristics). The transistors Q1 to Q6 areconnected in such a way as to allow switching between the L- and H-typecharacteristics and switching between forward and reverse rotation foreach type. The film winding motor M1 has its L terminal connected to thenode between the transistors Q1 and Q6, has its H terminal connected tothe node between the transistors Q2 and Q5, and has its common terminalconnected to the node between the transistors Q3 and Q4. Note that thefilm winding motor M1 winds the film F as it rotates in the forwarddirection.

As shown in Table 1, the transistors Q1 to Q6 are turned on or offappropriately so as to achieve switching of the film winding motor M1among states of resting, forward rotation (H- or L-type), reverserotation (H- or L-type), and braking (H- or L-type). Reference symbol C1represents a bypass capacitor that is inserted to prevent malfunctioningof the circuit by sufficiently suppressing variations that appear in theground (GND) voltage of the motor driving devices as a result of thefilm winding motor M1 being turned on and off repeatedly. Note that, inthis embodiment, H-type braking and H-type reverse rotation are notused.

Table 2 shows the relationship between the above-mentioned commands CMD0to CMD2 fed from the CPU 601 to the I/O IC 602 in order to turn on oroff the transistors Q1 to Q6 as shown above and the logic values fed outvia the output terminals P1 to P6 of the I/O IC 602.

Reference symbols Q7 and Q8 represent transistors for driving the chargemotor M2 for charging the aperture diaphragm locking member, the mirror,and the first and second blades of the shutter when they are unlocked byreleasing action. As shown in Table 3, the transistors Q7 and Q8 areturned on or off appropriately by the commands CMD3 and CMD4 fed fromthe CPU 601 so as to achieve switching of the charge motor M2 amongstates of resting, forward rotation, and braking. The charge motor M2achieves charging as it rotates in the forward direction.

Next, how the I/O IC 602 controls braking by reverse energizing will bedescribed. First, the film winding motor M1 is made to rotate in aforward direction to wind the film F. At the reverse energizing starttime described later, the film winding motor M1 is energized in thedirection reverse to the direction in which it has thus far beenenergized so that, while the rotation rate of the film winding motor M1is being monitored, the film winding motor M1 will be de-energized whenits rotation rate drops to zero, thereby completing the winding of thefilm F.

Here, if the film winding motor M1 is energized suddenly in the reversedirection, the supplied voltage +V_(DD) may drop abruptly, causingmalfunctioning of the transistor circuit. To prevent this, the suppliedvoltage is monitored within the I/O IC 602 so that, when the voltagedrops to such a low level that malfunctioning is likely, the filmwinding motor M1 will stop being energized momentarily and that, whenthe supplied voltage recovers its normal level, the film winding motorM1 will start being energized again. To achieve this, the I/O IC 602incorporates a comparator 602 b that receives, at one input terminal, areference voltage and, at the other input terminal, the suppliedvoltage. When the supplied voltage drops below the reference voltage,the comparator 602 b inverts its output level to turn off thetransistors Q4 and Q6 both.

Next, how the CPU 601 controls various operation routines will bedescribed with reference to the flow charts shown in FIGS. 7 to 20.First, the routine for film loading will be described. When the back lidof the body 70 is opened, a back lid lock switch SW7, which isinterlocked with a back lid lock mechanism, is turned on. Subsequently,after a film cartridge 74 is loaded into the film cartridge chamber 70 bin such a way that the perforations Fp of the leader portion of the filmF housed in the film cartridge 74 reach the circumferential surface ofthe spool 27, when the back lid is shut, the film cartridge 74 ispressed by the back lid, and thus the switch SW5 is turned on. On theother hand, the film F is pressed by the pressing plate 71 fitted to theback lid, and thus the switch SW6 is also turned on. When the back lidis shut completely, the back lid lock switch SW7 is turned off. Ondetecting this, the CPU 601 starts the initial loading routine shown inFIG. 7.

In the initial loading routine, first, in step #10, the state of theswitch SW5 is checked. If the switch SW5 is off, the film cartridge 74is recognized to be absent, and thus the flow returns to the mainroutine without performing initial loading. If the switch SW5 is on, theflow proceeds to step #12 to check the state of the switch SW6. If theswitch SW6 is off, the film F is recognized to be loaded improperly, andthe flow proceeds to an initial loading failure handling routine to warnof the failure of initial loading on the display, with a buzzer, or thelike.

When the back lid is shut with the film loaded properly, the flowproceeds to step #14 to set an initial-loading-in-progress flag at 1 andthen to step #16 to set a pulse 1 counter A at 0 and a pulse 2 counter Aat 32. This value 32 is used in initial loading to wind the film F to aposition for photographing the first frame. The pulse 1 counter A is acounter for storing the number of pulses 1 generated in a period inwhich no pulse 2 is generated, and the pulse 2 counter A is a counterfor storing the number of pulses 2 (pulses generated by the switch SW3mentioned previously) that are generated as extra pulses until the filmwinding motor M1 is stopped.

Next, in step #18, the film winding motor M1 is driven in L-type forwardrotation to start initial loading. At this time, the film winding motorM1 is energized in such a way that its gear 1 b rotatescounter-clockwise in FIG. 2. The reduction gear 2 rotates clockwise andthus causes, through the torsion coil spring 3, the reduction gear 4 torotate clockwise. The encoder gear 5 rotates counter-clockwise, and thephotointerruptor 6 outputs a pulse 1. In response to this pulse 1, instep #20, the flow is permitted to jump to the pulse 1 interrupthandling routine. On the other hand, the gear 20 rotatescounter-clockwise, and the planet lever 22 rotates counter-clockwise.

The gear 35 rotates clockwise, and the rewinding planet gear 37 rotatescounter-clockwise. During film winding, the cam portion 30 b of the camgear 30 is in a state as shown in FIG. 4A, and the projection 36 b ofthe rewinding planet lever 36 is kept in contact with the cam portion 30b of the cam gear 30. This prevents the rewinding planet lever 36 fromrotating clockwise, and thus the rewinding planet gear 37, unable tomesh with the rewinding gear 39, rotates idly. Accordingly, the rotationof the film winding motor M1 is not transmitted to the rewinding fork42.

The planet lever 22 rotates counter-clockwise without its side portion22 a making contact with the side portion 36 c of the rewinding planetlever 36, and, when the planet gear 21 meshes with the large gearportion 23 a of the spool drive gear 23, strikes a stopper (not shown)and stops there. As a result, the spool drive gear 23 rotatescounter-clockwise. Then, the small gear portion 23 b of the spool drivegear 23 makes the spool 27 rotate counter-clockwise. Then, the claw 27 bprovided on the spool 27 engages with the perforations Fp of the film Fand thereby the film F is taken out of the film cartridge 74 so as to bewound around the spool 27.

At this time, the movement of the film F causes the sprocket 50 torotate counter-clockwise, and thus the switch SW3 outputs a pulse 2. Inresponse to this pulse 2, the CPU 601 requests an interrupt, designatingthe pulse 2 interrupt handling routine as the target of the interrupt towhich the flow should jump (step #22). Then, in step #24, the timer TMR2interrupt handling routine is designated as the target of the interruptof the timer TMR2, and the timers TMR1 and TMR2 are started (step #26).Then, the film winding motor M1 starts being driven and, a period oftime t1 thereafter (step #28), the film winding motor M1 is driven inH-type forward rotation (step #30). Then, the flow waits the pulse 2counter A to become equal to 1 (step #32).

FIGS. 11 and 12 show the pulse 1 interrupt handling routine executedmeanwhile. In FIGS. 11 and 12, first, in step #200, the count value ofthe timer TMR2 is read out and stored in the RAM. Next, the pulse 1counter A is incremented by 1 (step #202), and whether or not the countvalue of the pulse 1 counter A is equal to or greater than N1 is checked(step #204). If the count value of the pulse 1 counter A is equal to orgreater than N1, then, in step #206, a pulse 2 interrupt is permitted.

Here, it is to be noted that the switch SW3 is composed of a circuitboard and sliding armatures and therefore that chattering is very likelyimmediately after the switch SW3 is turned on. Accordingly, if a pulse 2interrupt is permitted immediately after completion of a pulse 1interrupt, chattering in the pulse 2 may incur an undesired interrupt.To prevent this, it is desirable to wait for SW3 to become stable in theoff state.

However, permitting an interrupt by the use of a timer as describedabove may cause, depending on the rotation speed of the film windingmotor M1, the on period of the switch SW3 to become so long that theswitch SW3 is kept on even after the end of a specified period of time.To prevent this, the number of pulses 1 that are expected to be outputwhile the pulse 2 is on is set at N1 so that an interrupt will bepermitted when a number N1 of pulses are received.

Next, in step #208, whether or not the pulse 1 counter A is equal to orgreater than N2 is checked. Here, error detection as required in initialloading is performed. Specifically, if the claw 27 b of the spool 27 isnot engaged with the perforations Fp of the film F, or if the claw 27 bof the spool 27 disengages from the perforations Fp of the film F whilethe film F is being wound tight around the spool 27, the spool 27rotates idly and thus it is impossible to wind the film F. In such acondition, whereas the photointerruptor 6 outputs pulses 1, the switchSW3 outputs no pulse 2.

In step #208, whether the camera is in such a condition or not ischecked. Specifically, if the count value of the pulse 1 counter A isequal to or greater than N2, whether initial loading is in progress ornot is checked (step #234). If initial loading is in progress, the flowproceeds to the initial loading failure handling routine in step #238 towarn of the failure of initial loading on the display, with a buzzer, orthe like. If initial loading is not in progress, the flow proceeds to anerror detection routine (step #236). If the count value of the pulse 1counter A is smaller than N2, whether reverse energizing is in progressor not is checked (step #210). If reverse energizing is not in progress,the flow proceeds to step #230 to restart (start again) the timer TMR2and then set the timer TMR2 counter at 0, thereby ending the interrupthandling routine (step #232).

Now, how the timer TMR2 operates will be described. The timer TMR2requests an interrupt every a predetermined period of time t2; that is,after the timer starts counting time, the flow jumps to the timer t2interrupt handling routine shown in FIG. 16 every time a period of timet2 elapses.

In FIG. 16, first, in step #350, the count value of the timer TMR2counter is incremented by 1. The value obtained by multiplying the countvalue of the timer TMR2 counter by t2 represents the period of time thathas elapsed after the output of a pulse 1, and thus this period of timecan be determined by checking the count value of the timer TMR2 counter(step #352). If the next pulse 1 is not generated before a period oftime N3×t2 elapses, it is recognized that the film winding load is sogreat that the film cannot be driven by H-type driving, which offers alow torque.

Therefore, when the count value of the timer TMR2 counter reaches N3,the driving of the film winding motor M1 is switched from H-type forwarddriving to L-type forward driving to increase the torque of the filmwinding motor M1 (step #356). If, even with the increased torque of thefilm winding motor M1, the count value of the timer TMR2 counter reachesN4 before the next pulse 1 is generated (“yes” in step #354), it islikely that the film F is being strained at its tail end, preventing thespool 27 from rotating counter-clockwise, because, in such a case,slipping occurs between the reduction gear 2 and the torsion coil spring3, causing the encoder gear 5 to stop rotating, and thus thephotointerruptor 6 outputs no pulse 1. Accordingly, taking such a caseinto consideration, the flow proceeds to a film strain handling routine(step #358).

FIG. 13 shows the pulse 2 interrupt handling routine 1. First, in step#250, a pulse 2 interrupt is inhibited, and the pulse 2 counter A isdecremented by 1 (step #252). Next, the count value of the pulse 1counter A is read out and the number of pulses 1 that have beengenerated after a pulse 2 was generated last time is stored in the RAMof the CPU 601; similarly, the time counted by the timer TMR1, i.e. theperiod of time that has elapsed after a pulse 2 was generated last time,is read out and stored in the RAM (steps #254, #256). Then, to preparefor storage of the values that will be obtained when a pulse 2 isgenerated next time, the addresses in the RAM at which those values willbe stored are each incremented by 1 (step #258). In addition, the pulse1 counter A is set at 0 (step #260), and the timer TMR1 is restarted(step #262). Then the flow returns to the parent routine.

During film winding, whereas the torsion coil spring 24 and the springbarrel 25 rotate together with the spool drive gear 23, slipping occursbetween the torsion coil spring 26 and the spring barrel 25. Asdescribed previously, the slipping torque here is very small, andtherefore the loss in the winding force can be ignored.

Back in FIG. 7, as the winding of the film proceeds, when the countvalue of the pulse 2 counter A becomes equal to 1 (“yes” in step #32),the flow proceeds to step #34 to stop the film F accurately in theposition for photographing the first frame. In step #34, in accordancewith the values previously stored in the RAM, i.e. the number of pulses1 generated in a period in which no pulse 2 is generated and the timeinterval of pulses 2, the number of pulses 1 that are generated afterthe count value of the pulse 2 counter A became equal to 1 until brakingis applied by reverse energizing is determined by substitutingappropriate values in a formula prepared in advance.

Specifically, first, the number L(n), shown in FIG. 21, of pulses 1 thatare generated after the count value of the pulse 2 counter A becameequal to 1 until the time at which the film is expected to reach thetarget stop position is determined. The target stop position of the filmdoes not depend on the type of the film but depends on the number ofexposures that can be made on the film. Therefore, the number L(n) ofpulses 1 is a constant that corresponds to the film counter. Next, thenumber S(n), shown in FIG. 21, of pulses that are generated duringreverse energizing is determined.

When the number S(n) of pulses that are generated during reverseenergizing is determined, then, from L(n) and S(n), the number M(n),shown in FIG. 21, of pulses 1 that are generated after the pulse 2counter A was in the state indicated by (1) until reverse energizing isstarted. The film winding motor M1 is not free from variations in itscharacteristics, which may cause slight deviations in the stop positionof the film F from camera to camera. For this reason, the parametersused in the above-mentioned formula include an adjustment value(stopping constant) described later that are set on completion of themanufacture of the camera or before its sale to a user.

After calculating the number of pulses 1 that are generated untilreverse energizing is started, a setting is made such that an interruptwill be requested when the thus calculated number of pulses have beengenerated (step #38), with the reverse energizing interrupt handlingroutine shown in FIG. 14 designated as the target of the interrupt. Inaddition, the number of pulses 1 that are expected to be generatedduring reverse energizing is determined beforehand by calculation instep #36. When the predetermined number of pulses 1 are generated and aninterrupt is requested, the flow jumps to the reverse energizinginterrupt handling routine shown in FIG. 14.

In FIG. 14, in step #280, a reverse-energizing-in-progress flag is setat 1, and then pulse 1 counters B and C are set at 0 and 2, respectively(step #282). The pulse 1 counter B counts and stores the number ofpulses 1 that are generated during reverse energizing, and the pulse 1counter C is decremented by 1 when the number of pulses 1, i.e. theperiod of time, counted this time is shorter than the period of timecounted last time. Next, the film winding motor M1 is energized in sucha way as to be driven in L-type reverse rotation, and the flow returnsto the parent routine (step #288). Steps #284 and #286 will be describedlater.

As a result of reverse energizing, the speed of the gear 1 b of the filmwinding motor M1 drops abruptly. Meanwhile, when a pulse 1 is generatedduring reverse energizing, steps #200 to #210 of the interrupt handlingroutine shown in FIG. 11 are executed. Thereafter, the flow proceeds tostep #212 shown in FIG. 12 to compare the period of the pulses 1determined this time in step #200 with the period determined last timeand store the value determined in step #200 in the RAM of the CPU 601.Here, if the period of time counted this time is longer, the filmwinding motor M1 is recognized to be gradually coming to rest(approaching the stop position). In this case, the flow proceeds to step#214, where the pulse 1 counter C is set at 2, then to step #230, wherethe timer TMR2 is restarted, and then returns to the parent routine.

By contrast, when the period of time as represented by the number ofpulses 1 is shorter this time than last time, the pulse 1 counter C isdecremented by 1 (step #216). When the count value of the pulse counterC becomes equal to 0 (“yes” in step #218), the film winding motor M1 isrecognized to have come to rest once and then started to rotate its gear1 b clockwise, i.e. in the direction reverse to the direction in whichit has thus far been rotating. In this case, in step #219, the filmwinding motor M1 is driven in L-type forward rotation for apredetermined period of time, and then, in step #220, the film windingmotor M1 is stopped (see FIG. 21). Note that, for example when reverseenergizing has just been started, the pulses 1 may be generated atvarying intervals and this may cause the period of time counted thistime to be regarded as shorter than last time. For this reason, if, instep #218, the count value of the pulse 1 counter C is not equal to 0,the flow immediately returns to the parent routine.

When the gear 1 b of the film winding motor M1 rotates clockwise, thegear 20 rotates clockwise, and the planet lever 22 also rotatesclockwise, thereby disengaging the planet gear 21 from the large gearportion 23 a of the spool drive gear 23. At this time, the film F tendsto become loose owing to its own resilience, and thus the spool 27 tendsto rotate clockwise. However, since the slipping torque in the looseningdirection of the spool drive gear 23 and the torsion coil spring 24 isset to be greater than that resilience, the spool 27 and the spool drivegear 23 do not rotate clockwise, and thus the film F remains held bybeing wound tight around the spool 27.

If the planet lever 22 continues rotating clockwise, the planet gear 21will eventually mesh with the gear portion 30 a of the cam gear 30.However, the film winding motor M1 is de-energized before that toprevent the planet gear 21 from meshing with the gear portion 30 a ofthe cam gear 30. On the other hand, if, during reverse energizing, thefilm F is wound up to its tail end and is strained there, the speeddrops to 0 faster than otherwise. This causes the pulse intervals tobecome shorter faster, and thus causes the motor to stop earlier, thanexpected.

Accordingly, the number of pulses 1 actually generated is compared withthe number of pulses 1 determined, as expected during reverseenergizing, in step #36 shown in FIG. 7 (step #224) so that, if thenumber of pulses 1 actually generated is smaller than the number ofpulses 1 expected, the flow will proceed to step #240 to execute thefilm strain handling routine. When as many pulses 1 as expected aregenerated, initial loading is finished, and theinitial-loading-in-progress flag is reset to 0 (step #40), therebybringing the camera into a state ready for photographing.

Now, the method of calculating the adjustment value (stopping constant)used as a parameter in the formula for determining the reverseenergizing start time will be described. First, the film F istransported a predetermined number of frames, and a signal requestingstarting of a reverse energizing start time adjustment mode is fed tothe CPU 601 from the outside through an operation member (not shown). Inresponse to this signal, the CPU 601 starts executing the reverseenergizing start time adjustment routine shown in FIG. 20.

In FIG. 20, first, in step #500, a pulse 1 counter E is cleared to 0.The pulse 1 counter E is a counter that is incremented by 1 every time apulse 1 is generated. Next, in steps #502 to #506, the film windingmotor M1 is driven in L-type forward rotation, and a period of time t1thereafter, the driving of the film winding motor M1 is switched toH-type forward rotation. Next, in steps #508 to #512, the points of timeat which the count value of the pulse 1 counter E becomes equal to N5and N6, respectively, are determined, and the period of time thatelapses while the pulses 1 are counted from N5 to N6 is calculated onthe basis of the number of pulses 1 so as to determine the average speedv of the film winding motor M1 immediately before starting of reverseenergizing (step #514). Note that the value of N6 is so set as to beapproximately equal to the number of pulses 1 that are generated, inactual film winding, after the motor starts being driven until reverseenergizing is started.

Next, the driving of the film winding motor M1 is switched to L-typereverse rotation (step #516). Then, while the pulses 1 that aregenerated during reverse energizing are counted (step #518), the reverseenergizing stop time at which the period of the pulses 1 determined thistime becomes shorter than last time is waited for (step #520). At thereverse energizing stop time (“yes” in step #520), the film windingmotor M1 is stopped (step #522). Here, the number of pulses 1 that aregenerated after the starting of energizing until de-energizingrepresents the amount of rotation that the film winding motor M1actually makes while its speed changes from v to 0. Accordingly, theadjustment value is calculated from this number of pulses 1 and thespeed v (step #524), and the adjustment value thus calculated is writtento the EEPROM (step #526). This is the end of the reverse energizingstart time adjustment routine.

The use of the adjustment value (stopping constant) thus obtainedpermits the formula for determining the time at which to apply brakingby reverse energizing to reflect reality more accurately. This helpscancel variations in the characteristics of the motor, and thereby makesit possible to stop the film F more accurately in a desired position. Inthis adjustment mode, operations are performed after transporting thefilm F a predetermined number of frames in order to simulate realitymore accurately. Instead of this method, which requires a considerablylong time by involving steps such as loading the film F and transportingit a predetermined number of frames, it is also possible to performadjustment beforehand without loading the film and compensate for thedifference from the case where the film is loaded afterwards when theadjustment value is calculated next time.

Next, how photographing proceeds will be described. When a releasebutton (not shown) is pressed halfway in, and thereby the switch SWi isturned on, the switch SW1 interrupt handling routine shown in FIG. 8 isexecuted. In step #700, the CPU 1 starts serial communication with thephotometer 606 to perform photometry, and then, in step #702, the CPU 1starts serial communication with the focus detection module 603 andvarious controllers to perform focus detection.

In step #704, an AF pulse is set for a target value based on the resultof focus detection, and the lens drive motor M3 starts being driven.Then, an AF pulse interrupt is permitted. In step #706, an interrupt ofthe switch SW2, which is turned on when the release button is pressedfully in, is permitted. Then, in step #708, steps #700 to #706 areperformed repeatedly as long as the switch SW1 remains on. When theswitch SW1 is turned off, i.e. when the release button is released, thecamera is brought into a sleep state (step #710).

As the lens drive motor M3 moves, the AF pulse interrupt handlingroutine shown in FIG. 9 is executed, and, every time an interrupt isrequested, an AF pulse counter is incremented by 1 in step #740. Insteps #742 and #744, the lens drive motor M3 is driven until the countvalue of the AF pulse counter reaches the target value set, when thelens drive motor M3 is stopped to finish lens movement.

When the release button is pressed fully in, the switch SW2 is turned onwhile the switch SW1 remains on, and the flow jumps to the SW2 interrupthandling routine shown in FIGS. 22 to 24 to perform releasingoperations. In FIG. 22, first, in step #800, whether a flag is 1 or notis checked. This flag is set at 1 when a mode for high-speed continuousphotographing is established (step #894 described later). Hereafter,this mode will be referred to as the “flying release mode”, and thisflag will be referred to as the “flying flag”.

If the flying flag is 0, then, in step #802, an IP (imprint) signal thatrequests imprinting of photographing data such as a date on the film Fis output, and then the duration of imprinting is set in an IP timer.When a predetermined period of time set in the IP timer elapses, the IPtimer interrupt handling routine shown in FIG. 25 is executed, and then,in step #740, the IP signal ceases to be output.

Back in FIG. 22, in step #804, whether to perform automatic focusingeven when the mirror is lifted up so as to be retracted from the opticalpath as in cases where, for example, the object is moving is determined.If automatic focusing is to be performed, then, in step #806, an AFpulse is set at a target value based on the result of focus detection,and then the lens drive motor M3 starts being driven. Then, an AF pulseinterrupt is allowed, and the AF pulse interrupt handling routine shownin FIG. 9 is executed in the same manner as described above to performAF operations.

When the flying flag is 1, to permit high-speed continuousphotographing, exposure preparation operations are performed withoutoutputting the IP signal or performing AF operations during thelifting-up of the mirror. First, in step #810, the film winding motor M1and the charge motor M2 are turned off. Here, if the flying flag is 0,film feeding and charging are complete, and therefore the motors M1 andM2 are both off. In step #812, the releasing magnet RMg and the firstand second shutter blade holding magnets 1CMg and 2CMg are energized.When the releasing magnet RMg is energized, the charge lever 117 shownin FIG. 5 moves in the direction indicated by (A).

Then, the aperture diaphragm and the mirror are unlocked so that theaperture diaphragm is capable of being stopped down and the mirror iscapable of being lifted up so as to be retracted from the optical path.On the other hand, the first and second blades of the shutter, which areunlocked by energizing the releasing magnet RMg, are then held byenergizing the first and second shutter blade holding magnets 1CMg and2CMg. The purpose of turning off the motors M1 and M2 is to secure asufficient supplied voltage for the releasing magnet RMg and the firstand second shutter blade holding magnets 1CMg and 2CMg, which requirelarge amounts of current to operate. The duration for which thesemagnets are energized is about 5 milliseconds, and therefore, eventhough the motors M1 and M2 are stopped momentarily, it is possible toperform continuous photographing at satisfactorily high speed.

Next, the number of aperture pulses corresponding to a predeterminedaperture value is calculated (step #814), and then whether thepredetermined aperture value is the open aperture value or not ischecked (step #816). If so, the releasing magnet RMg is turned off tolock the aperture diaphragm (step #830), and then, if the flying flag is1, the driving of the motors M1 and M2 is restarted (steps #832, #834).Since the duration for which the film winding motor M1 is stoppedmomentarily is about 5 milliseconds as described above, the driving ofthe film winding motor M1 is restarted in H-type high-speed rotation.

If, in step #816, the predetermined aperture value is not the openaperture value, the aperture diaphragm, which has been unlocked by thereleasing magnet RMg, starts aperture adjusting motion, while detectionof a first aperture pulse is waited for (step #818). When a firstaperture pulse is detected and thereby starting of aperture adjustingmotion is recognized, then, in step #820, the releasing magnet RMg isturned off and simultaneously the aperture diaphragm locking magnet FMg,which requires a smaller amount of current than the releasing magnetRMg, is energized to keep the aperture diaphragm in an unlocked state.

When the flying flag is 1, the driving of the film winding motor M1 isrestarted in H-type rotation, and the driving of the charge motor M2 isalso restarted (steps #822, #824). Thereafter, in step #826, pulses arecounted until the number of counted pulses coincides with the number ofaperture pulses calculated in step #814. When the calculated number ofpulses have been generated, then, in step #828, the aperture diaphragmlocking magnet FMg is turned off to stop the motion of the aperturediaphragm.

If, in step #839 shown in FIG. 23, the flying flag is 1, the filmwinding motor M1 is driven to transport the film F until the count valueof the pulse 2 counter A becomes equal to 2 (step #840). When the countvalue of the pulse 2 counter A becomes equal to 2, the operations forstopping the film winding motor M1 start being performed in the samemanner as in initial loading. In step #842, on the basis of the valuespreviously obtained and stored in the RAM, i.e. the number of pulses 1generated in a period in which no pulse 2 is generated and the timeinterval of pulses 2, the number of pulses 1 that are generated afterthe count value of the pulse 2 counter A became equal to 2 until brakingis applied by reverse energizing is determined by substitutingappropriate values in a formula prepared in advance.

After calculating the number of pulses 1 that are generated untilreverse energizing is started, a setting is made such that an interruptwill be requested when the thus calculated number of pulses have beengenerated (step #844), with the reverse energizing interrupt handlingroutine shown in FIG. 14 designated as the target of the interrupt. Whenthe predetermined number of pulses 1 are generated and an interrupt isrequested, the flow jumps to the reverse energizing interrupt handlingroutine shown in FIG. 14.

In step #846, whether, as a result of execution of the pulse 1 counterinterrupt handling routine (see FIGS. 11 and 2), winding is complete andthus a winding-complete flag is 1 or not is checked. When the lever 115(see FIG. 5) moves back to its original position and charging iscomplete, the switch SW4 is turned on, and the switch SW4 interrupthandling routine (see FIG. 15) is executed, thereby setting acharging-complete flag at 1. In step #848, whether the charging-completeflag is 1 or not is checked. The checks in steps #846 and #848 areperformed to prevent starting of exposure when winding is stopped as aresult of the film being strained at its tail end or when charging ofthe shutter is stopped half-finished.

In step #850, the flow waits for a predetermined period of time toelapse that is long enough to allow confirmation of completion ofphotometry with the aperture diaphragm fully stopped down by thereleasing magnet RMg energized and with the mirror free of boundingmovement (vibration) after detection of completion of its charging. Thishelps prevent erroneous execution of the exposure operations describedbelow.

After the lapse of the predetermined period of time, in step #852, thefirst shutter blade holding magnet 1CMg is de-energized, and thus thefirst blade of the shutter is opened to start exposure. After waitingfor a period of time to elapse that corresponds to the shutter speed Tv(step #854), in step #856, the second shutter blade holding magnet 2CMgis de-energized, and thus the second blade of the shutter is closed toend exposure. After waiting for a predetermined period of time t3 toelapse that is required for the second blade of the shutter to completeits movement (step #858), the flow proceeds to film winding operationsfor transporting the film one frame and charging the shutter and othercomponents in preparation for the next shot In step #860, to transportthe film F and charge the shutter and other components, the film windingmotor M1 is driven in L-type forward rotation and simultaneously thecharge motor M2 is driven in forward rotation. Film winding is performedin the same manner as in initial loading. Specifically, as the gear 1 brotates counter-clockwise, the film F is wound around the spool 27, andmeanwhile the photointerruptor 6 and the switch SW3 generate pulses 1and pulses 2, respectively. In step #862, the timers TMR1 to TMR3 arerestarted, and then, in steps #864 to 868, various interrupts arepermitted in the same manner as described previously.

On completion of charging, the switch SW4 is turned on. Therefore, aninterrupt of this switch SW4 is additionally permitted in step #870.Then, in step #872, the charging-complete flag, the winding-completeflag, and the flying flag are reset to 0, and then, in step #874, theflow waits for the switch SW9, which is turned on when charging of themirror is complete, to be turned on. When the switch SW9 is turned on,then, in step #876, the timer TMR3 is stopped, and the period of timerequired to charge the mirror is read out.

In step #880, the period of time read out from the timer TMR3 iscompared with a predetermined period of time Ta. If the former is equalto or shorter than the latter, the flow waits for a period of time t7 toelapse (step #882); if the former is longer than the latter, the flowwaits for a period of time t8 to elapse (step #884). This wait issecured to wait for the bounding movement (vibration) of the mirror, asoccurs when its charging is complete, to die away until the mirrorbecomes stable. When charging of the mirror takes a short time, i.e.when the mirror is moved at high speed, a large amount of boundingoccurs, and therefore a wait of a long period of time t7 is secured;when charging of the mirror takes a long time, i.e. when the mirror ismoved at slow speed, a small amount of bounding occurs, and therefore await of a short period of time t8 is secured.

Next, in step #886, photometry is performed in preparation forcontinuous photographing, and then, in step #888, the period of timeread out from the timer TMR3 is compared with a predetermined period oftime Tb. If the period of time read out from the timer TMR3 is equal toor shorter than the predetermined period of time Tb, and in addition theswitch SW10 for switching to continuous photographing is on (step #890),and in addition the switch SW2 is on (step #892), then, in step #894,the flying flag is set at 1 and the SW2 interrupt handling routine isrepeated.

If the period of time read out from the timer TMR3 is longer than thepredetermined period of time Tb, or the switch SW10 is off, or theswitch SW2 is off (steps #888 to #892), then a photographing mode (forsingle-shot photographing or low-speed continuous photographing) isestablished that consists of steps starting with step #896.

When the supplied voltage is low, it is difficult to operate the camerain the flying release mode, which requires simultaneous activation ofvarious actuators to achieve high-speed operation. Therefore, when thetime required to charge the mirror is longer than the predeterminedperiod of time Tb, the supplied power is recognized to be low, and theflying release mode is not established. In this case, charging and filmfeeding require an accordingly long time, and therefore, even if theflying release mode is established, it is impossible to performhigh-speed continuous photographing, and thus it is quite reasonable toperform low-speed continuous photographing instead.

In single-shot photographing and low-speed continuous photographing,focus detection is performed. Focus detection is achieved by the use ofthe light reflected from a sub-mirror coupled to the mirror, andtherefore, first, in step #896, the flow waits for a period of time t9to elapse to allow the bounding movement of the sub-mirror to die away,and then, in step #898, focus detection is performed. Then, in steps#900 to #908, as in steps #840 to #848, the film winding motor M1 isstopped, and, after confirming that the winding-complete flag and thecharging-complete flag are 1, the switch SW1 interrupt handling routineis repeated.

In this way, in the switch SW2 interrupt handling routine, if thesupplied voltage is sufficient, continuous photographing is performed inthe flying release mode (with the flying flag set at 1), and thusexposure preparation operations are started after completion of chargingof the mirror and the aperture diaphragm (with the switch SW9 turned on)and before completion of charging of the shutter and transporting of thefilm. This makes high-speed continuous photographing possible.

However, if the film F is broken for some reason, or if the film F woundtight around the spool 27 becomes so loose as to make winding of thefilm impossible, whereas the photointerruptor 6 outputs pulses 1, theswitch SW3 outputs no pulse 2. Therefore, as in initial loading, in step#208 of the pulse 1 interrupt handling routine (FIG. 11), whether thecount value of the pulse 1 counter A is equal to or greater than N2 ornot is checked. If the count value of the pulse 1 counter A is equal toor greater than N2, then the flow proceeds to step #234 and, sinceinitial loading is not in progress, further to step #236 to execute theerror detection routine (not shown). In the error detection routine, themotors M1 and M2 are stopped, and then a buzzer or the display warns theuser of an error.

On the other hand, when the charge motor M2 is energized and thereby,through the reduction gear 111, the charge cam 112 rotates clockwise inFIG. 5, the cam 112 a of the charge cam 112 rotates the lever 115counter-clockwise against the force with which it is loaded by thespring 116 so as to press the charge lever 117 in the direction (B) andthereby charge the aperture diaphragm, the mirror, and the shutter. Whenthe charge cam 112 starts rotating, the switch SW4 immediately turnsfrom on to off. When the charge cam 112 makes substantially one turn,the charge lever 117 is locked to complete charging of the aperturediaphragm, the mirror, and the shutter. Subsequently, when the lever 115is rotated clockwise by the spring 116 until it falls into that portionof the cam 112 a where its radius is smallest, the switch SW4 is turnedon again.

When the switch SW4 is turned from off to on as described above, aninterrupt is requested, and the flow jumps to the switch SW4 interrupthandling routine shown in FIG. 15. In the switch SW4 interrupt handlingroutine shown in FIG. 15, first, the charging-complete flag is set at 1(step #320), and then braking is applied to the charge motor M2 (step#322). A period of time t4 thereafter, an interrupt is requested, andthe timer TMR3 for stopping the charge motor M2 is set (step #324).

When the film winding motor M1 is driven by reverse energizing beforecompletion of charging of the aperture diaphragm, the mirror, and theshutter, the voltage fed to the motors drops so greatly that it isimpossible to drive the charge motor M2. To prevent this, in step #284shown in FIG. 14, the charging-complete flag is checked. If thecharging-complete flag is 0, it is recognized that charging is notcomplete yet, and the charge motor M2 is stopped (step #286). Aftercompletion of reverse energizing, in step #225 shown in FIG. 12, thewinding-complete flag is set at 1, and then, in step #226, thecharging-complete flag is checked again. If the charging-complete flagis 0, charging is not complete yet, and thus the charge motor M2 isdriven again to charge the aperture diaphragm, the mirror, and theshutter (step #228).

If the film F is strained at its tail end, in the same manner as whenfilm strain occurs in initial loading, slipping occurs between thereduction gear 2 and the torsion coil spring 3. As a result, thephotointerruptor 6 ceases to output pulses 1, and thus the flow jumps tothe timer TMR2 interrupt handling routine shown in FIG. 16. Here, thefilm winding motor M1 is first driven in L-type rotation, and, apredetermined period of time thereafter, the flow proceeds to step #358to execute a film strain handling routine. In this embodiment, the filmstrain handling routine is the same as the rewinding routine shown inFIG. 10.

Next, the rewinding routine will be described. When the film F is foundstrained in one of the operation routines, or when a switch (not shown)that is pressed when the user wishes to rewind the film F half-used isfound pressed, the flow jumps to the rewinding routine shown in FIG. 10.

First, in step #150, the rewinding-in-progress flag is set at 1, andthen a pulse 1 interrupt 2 and a timer TMR2 interrupt 2 are permitted(steps #152 to #154), with the pulse 1 interrupt handling routine 2 andthe timer TMR2 interrupt handling routine 2 designated as theirrespective target interrupts. Permitting these interrupts makes itpossible to detect failure to drive the film winding motor M1 owing tosome error arising when the cam gear 30 is rotated as will be describedlater.

In the pulse 1 interrupt handling routine 2 shown in FIG. 18, while thepulse 1 counter A is counting pulses 1 that are generated while a pulse2 is being generated, the timer TMR2 is restarted (steps #400 to #404).If no pulse 1 is generated before a predetermined period of time elapses(before the count value of the timer TMR2 counter becomes equal to N4),the flow proceeds from step #422 shown in FIG. 19 to step #424 toexecute the error detection routine.

Next, in step #156, the film winding motor M1 is driven in L-typereverse rotation, and the flow waits for the switch SW8 to be turned off(step #158). When the film winding motor M1 is driven in L-type reverserotation, the gear 1 b rotates clockwise, and the gear 20 rotatesclockwise. As a result, the planet lever 22 rotates clockwise untileventually the planet gear 21 meshes with the gear portion 30 a of thecam gear 30. When the planet lever 22 strikes a stopper (not shown) andthus stops rotating, the rotation of the gear 20 is transmitted throughthe planet gear 21 to the cam gear 30, causing the cam gear 30 to rotateclockwise.

Then, as shown in FIG. 4B, the projection 36 b of the rewinding planetlever 36 is released from the cam portion 30 b of the cam gear 30, andthen the rewinding planet lever 36 is rotated clockwise by the spring38. When the rewinding planet gear 37 meshes with the rewinding gear 39,it strikes a stopper (not shown) and thus stops. Moreover, as therewinding planet lever 36 rotates clockwise, its bent portion 36 a makesthe arm 26 b of the torsion coil spring 26 rotate counter-clockwise soas to remove the tightening force of the torsion coil spring 26. On theother hand, the switch SW8 is turned off when the cam portion 30 b ofthe cam gear 30 is well away from the projection 36 b of the rewindingplanet lever 36. When the switch SW8 is turned off, braking is appliedto the film winding motor M1 for a period of time t5 (step #160) so asto stop the rotation of the cam gear 30.

Then, the film winding motor M1 is driven in L-type forward rotation(step #162), and this makes rewinding possible. At this time, the gear20 rotates counter-clockwise and the planet lever 22 also rotatescounter-clockwise. However, in the middle of this rotation, the sideportion 22 a of the planet lever 22 strikes the side portion 36 c of therewinding planet lever 36 so as to prevent such rotation, and thus theplanet gear 21 rotates idly without engaging with the large gear portion23 a of the spool drive gear 23 nor the gear portion 30 a of the camgear 30 (FIG. 4C).

On the other hand, through the gear 35 and the rewinding planet gear 37,the rewinding gear 39 rotates clockwise, and thereby causes, through thegear train 40, the rewinding fork gear 41 and the rewinding fork 42 torotate clockwise so as to rewind the film F back into the film cartridge74. At this time, the encoder gear 5 rotates to cause thephotointerruptor 6 to output pulses 1. In addition, in synchronism withthe film F being rewound, the sprocket 50 rotates clockwise to cause theswitch SW3 to generate pulses 2.

Therefore, the pulse 1 interrupt handling routine 1, the pulse 2interrupt handling routine 2, and the timer TMR2 interrupt handlingroutine 2 are set (step #164). Here, the control flow is almost the sameas in initial loading, except that, as shown in FIG. 17, the pulse 2interrupt handling routine 2 simply clears the pulse 1 counter A to 0 instep #380 to allow detection (step #236) of an error such as breakage ofthe film F where the photointerruptor 6 outputs pulses 1 but the switchSW3 outputs no pulse. Then, in step #166, the flow waits for a period oftime ti to elapse, and then, in step #168, the film winding motor M1 isdriven in H-type forward rotation.

In film rewinding, as the film F moves, the spool 27 rotates clockwise ,and the spool drive gear 23 also rotates clockwise. At this time, thetorsion coil spring 26 exerts no tightening force, and therefore thespring barrel 25 can rotate clockwise with almost no resistance.Accordingly, the spool 27 rotates together with the torsion coil spring24 and the spool drive gear 23 and thus with almost no load. This helpsminimize the rotation force of the rewinding fork 42.

As film rewinding proceeds, when the head end of the film F passes thefilm detecting pin 60, the film detecting pin 60 is pressed toward thefilm F side by the film detecting armature 61, and thus the switch SW6is turned off. On detection of the switch SW6 being turned off (step#170), the flow waits for the photointerruptor 6 to generate so manypulses as corresponds to the amount of rotation of the rewinding fork 42that is equivalent to the length of the remaining leader portion of thefilm F so as to ensure that the film F will be rewound completely intothe film cartridge 74 (step #172). When the predetermined number ofpulses are generated, then, in step #174, braking is applied to the filmwinding motor M1 for a period of time t5 to stop it (step #176), andthen a pulse 2 interrupt is inhibited (step #178).

Now, film winding is complete. To restore the cam gear 30 back to itsposition for winding, in step #180, the film winding motor M1 is drivenin L-type reverse rotation. As a result, the cam gear 30 rotatesclockwise, and thus the cam portion 30 c of the cam gear 30 strikes theprojection 36 b of the rewinding planet lever 36 and thereby causes therewinding planet lever 36 to rotate counter-clockwise against the forcewith which it is loaded by the spring 38.

When the projection 36 b of the rewinding planet lever 36 runs onto thecam portion 30 b of the cam gear 30, the position for winding isrestored. At this time, the switch SW8 is turned on, and, on detectingthis in step #182, braking is applied to the film winding motor M1 for aperiod of time t6 to stop it (steps #184 and #186). This is the end ofall operations related to film rewinding, and a message indicatingcompletion of film winding is displayed on the display of the camera.This indication allows the user to open the back lid (not shown) to takeout the film cartridge 74 containing the exposed film.

TABLE 1 Q1 Q2 Q3 Q4 Q5 Q6 State of film winding motor M1 off off off offoff off Resting on off off on off off L-type Forward Rotation off on offon off off H-type Forward Rotation off off on off off on L-type ReverseRotation off off on off on off H-type Reverse Rotation off off off onoff on L-type Braking off off off on on off H-type Braking

TABLE 2 State of film wind- CMD0 CMD1 CMD2 P1 P2 P3 P4 P5 P6 ing motorM1 H H H H H H L L L Resting H L L L H H H L L L-type Forward Rotation HL H H L H H L L H-type Forward Rotation L H L H H L L L H L-type ReverseRotation L H H H H L L H L H-type Reverse Rotation L L L H H H H L HL-type Braking L L H H H H H H L H-type Braking

TABLE 3 CMD3 CMD4 Q7 Q8 State of charge motor M2 H H off off Resting L Hon off Forward Rotation H L off on Braking

What is claimed is:
 1. A camera comprising: a first charge mechanism forcharging a mirror; a second charge mechanism for charging an aperturediaphragm; a third charge mechanism for charging a shutter; an exposurepreparation mechanism for performing an exposure preparation operationin response to a releasing operation; a selector for distinguishingbetween single-shot photographing and continuous photographing; a firstdetector for detecting completion of charging of the mirror; a seconddetector for detecting completion of charging of the aperture diaphragm;a third detector for detecting completion of charging of the shutter;and a controller for executing a flow of control such that, when theselector detects continuous photographing being performed and inaddition the first and second detectors detect completion of charging ofthe mirror and the aperture diaphragm, the exposure preparationoperation is started irrespective of a result of detection by the thirddetector.
 2. A camera as claimed in claim 1, further comprising: a filmfeeder for feeding a film by one frame; and a film feeding completiondetector for detecting completion of one-frame feeding of the film,wherein the controller starts the exposure preparation operationirrespective of a result of detection by the film feeding completiondetector.
 3. A camera as claimed in claim 1, wherein the exposurepreparation mechanism is a mechanism for lifting up the mirror and forstopping down the aperture diaphragm.
 4. A camera as claimed in claim 1,wherein the controller starts the exposure preparation operation a firstpredetermined period of time after completion of charging of the mirroror the aperture diaphragm.
 5. A camera as claimed in claim 4, whereinthe controller varies the first predetermined period of time inaccordance with a period of time from starting to completion of chargingof the mirror.
 6. A camera as claimed in claim 1, wherein the controllerchanges e flow of control in accordance with a period of time fromstarting to completion of charging of the mirror.
 7. A camera as claimedin claim 6, wherein the controller stops executing the flow of controlwhen the period of time from starting to completion of charging of themirror is longer than a second predetermined period of time.
 8. A cameraas claimed in claim 1, further comprising: a focusing mechanism fordriving a taking lens so as to focus it on an object to be shot, whereinthe controller inhibits operation of the focusing mechanism whileexecuting the flow of control.
 9. A camera as claimed in claim 1,further comprising: an imprinter for imprinting photographing data on afilm, wherein the controller inhibits operation of the imprinter whileexecuting the flow of control.
 10. A camera as claimed in claim 2,wherein the controller starts an exposure operation when, after startingof the exposure preparation operation, the third detector detectscompletion of charging of the shutter and in addition the film feedingcompletion detector detects completion of feeding of the film.
 11. Acamera as claimed in claim 10, wherein the controller starts theexposure operation a third predetermined period of time after startingof the exposure preparation operation.
 12. A camera as claimed in claim2, wherein the exposure preparation mechanism has a magnet for unlockingat least one of the mirror, the aperture diaphragm, and the shutter, andthe controller de-energizes a motor for driving the camera when themagnet is activated.
 13. A camera as claimed in claim 12, wherein themotor for driving the camera is at least one of a motor for feeding thefilm or a motor for charging.